FIX: 修复 CI 测试失败

Author: echo-loop

lib/widgets/common/masked_sentence_tile.dart

@@ -307,10 +307,10 @@ class _SentenceBookmarkHitArea extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final l10n = AppLocalizations.of(context)!;
+    final l10n = AppLocalizations.of(context);
     final semanticLabel = isBookmarked
-        ? l10n.intensiveListenMarkedDifficult
-        : l10n.intensiveListenNotDifficult;
+        ? (l10n?.intensiveListenMarkedDifficult ?? 'Marked difficult')
+        : (l10n?.intensiveListenNotDifficult ?? 'Not marked difficult');
     final iconColor = isBookmarked
         ? Colors.amber
         : theme.colorScheme.onSurfaceVariant.withValues(alpha: 0.28);

test/services/storage_service_test.dart

@@ -15,7 +15,7 @@ void main() {
       await StorageService.saveSettings(
         const ListeningPracticeSettingsStore(
           full: PlaybackSettings(
-            playbackSpeed: 1.25,
+            playbackSpeed: 1.3,
             showTranscript: true,
             singleSentenceMode: false,
             wholeLoopCount: 4,
@@ -30,7 +30,7 @@ void main() {
       );
 
       final loaded = await StorageService.loadSettings();
-      expect(loaded.full.playbackSpeed, 1.25);
+      expect(loaded.full.playbackSpeed, 1.3);
       expect(loaded.full.showTranscript, isTrue);
       expect(loaded.full.singleSentenceMode, isFalse);
       expect(loaded.full.wholeLoopCount, 4);
@@ -69,5 +69,22 @@ void main() {
       expect(loaded.bookmark.sentenceLoopCount, 1);
       expect(loaded.bookmark.sentenceInterval, const Duration(seconds: 1));
     });
+
+    test('旧持久化中的非支持倍速读取时回退到 1.0x', () async {
+      final prefs = await SharedPreferences.getInstance();
+      await prefs.setString(
+        'playback_settings',
+        json.encode({
+          'fullSettings': const PlaybackSettings(playbackSpeed: 1.0).toJson()
+            ..['playbackSpeed'] = 1.25,
+          'bookmarkSettings':
+              const PlaybackSettings(playbackSpeed: 0.8).toJson(),
+        }),
+      );
+
+      final loaded = await StorageService.loadSettings();
+      expect(loaded.full.playbackSpeed, 1.0);
+      expect(loaded.bookmark.playbackSpeed, 0.8);
+    });
   });
 }